A conventional paper punch, especially a paper punch that is used for punching holes through a thick pile of paper sheets is disclosed in FIGS. 1 and 2, and generally includes a base 1 with a plurality of frames 2 extending from a top of the base 1, a handle 3 pivotably connected to the frames 2, a driving gear 4 co-rotatably connected to the handle 3, a punch head 5 connected to a top portion 7 and a rack 6 is fixed to the top portion 7 and engaged with the driving gear 4. When punching a thick pile of paper sheets 8 on the base 1, the user simply pivots the handle 3 downward and the driving gear 4 drives the rack 6 together with the top portion 7 downward, the punch head 5 penetrates through the pile of paper sheets 8. Although the mechanism composed of the driving gear 4 and the rack 6 provides a sufficient force to punch the paper sheets 8, the resistance from the paper sheets 8 is huge during the punching. It is noted that the travel of the pivotal movement of the handle 3 is over 90 degrees and this long travel makes the user change his or her arms to apply a continuous force to the handle 3. This change of arms could hurt the wrist. Some manufacturers increase the height of the frames 2 to increase the travel of the handle 3 to allow the angular travel of the handle 3 less than 90 degrees, this change increases the manufacturing cost and loses commercial benefits.
The present invention intends to provide a paper punch wherein the handle can be pivoted upward to the initial position while the punch head is stay in the paper sheets so that the angular travel of the handle is kept in a range that is less than 90 degrees.